To clarify the dispersive characterization of fibers in polyvinyl alcohol (PVA) fiber cement composites, the fluorescencecharacteristics and image of PVA fibers in the PVA fiber cement composites were determined by fluorescence spectrometer andfluorescence microscope coupled with image-processing software, respectively. The influences of mixing method, aspect ratio andvolume fraction of fibers and dispersing agent on the dispersion of PVA fibers were investigated. The experimental results show thatthe optimum wavelength ranges of excitation and emission wave of PVA fibers are 415–460 nm and 480–540 nm, respectively. Thus,a green fluorescent protein (GFP) filter can be chosen for fluorescence image analysis. Also, the dispersion of PVA fibers wasquantitatively evaluated by the distribution coefficient and effective utilization percentage in the fluorescence microscopy techniquebased on fluorescence image analysis. Compared to the control sample in the absence of a dispersing agent, the effective utilizationpercentage of fibers with 12 mm length, 27 μm diameter and 0.3% volume fraction in the PVA fiber cement composites in thepresence of a dispersing agent after the synchronous mixing for 6 min is increased by 32.9%.